Neighborhood Impact from Global Warming Outlined Online

Update: 9:43 p.m. EDT

Sea levels are rising at such a rate that, by 2050, coastal flooding will far exceed four feet above the local high-tide line, according to a research report released today.

Climate Central, a non-profit research group headquartered inPrinceton,N.J., says sea-level rise due to global warming “has doubled the annual risk of coastal flooding of historic proportions across widespread areas of theUnited States.”

The report says by 2030 many coastal areas of theUnited Stateswill likely see storm surge combining with sea-level rise to close to four feet above the local high-tide line.

It says close to 5 million people live in 2.6 million homes that sit on land below the four foot level.

The report, titled Surging Seas, “is the first to analyze how sea-level risk caused by global warming is compounding the risk from storm surges throughout the coastal contiguousU.S.”

The report also generates local and national estimates on the land, housing and population in vulnerable low-lying areas. The information is coupled with flood-risk timelines.

The report includes online, searchable maps that zoom down into neighborhoods to show risk zones and statistics for 3,000 coastal towns, cities, counties and states affected by seas up to 10 feet above the high-tide line.

Across every coastal state exceptMaineandPennsylvaniain the lower 48 states, there are 676 towns and cities that sit below the four-foot tidal mark, or more than 10 percent of the population.

“Sea-level rise is not some distant problem that we can just let our children deal with,” says Ben Strauss, lead author of the report in a statement. “The risks are imminent and serious.”

He says a small sea-level rise that will probably occur within the next 20 years “can turn yesterday’s manageable flood into tomorrow’s potential disaster. Global warming is already making coastal floods more common and damaging.”

The report says that global warming has raised sea levels by 8 inches since 1880 and levels are expected to rise 20 to 80 inches this century, depending on the amount of pollution emitted by man.

When asked to comment on the Climate Central research Peter Dailey, director of Atmospheric Science at AIR Worldwide, responded in an e-mail, saying “AIR, in collaboration with its sister company AER, have published peer reviewed research showing that recent trends in rising sea levels may lead to significantly elevated risk of coastal storm surge in conjunction with land falling hurricanes. Portions of the U.S. coastline are particularly sensitive to small changes in sea level—such as the Louisiana coastline and the New Orleans metropolitan area—where hurricanes can bring strong coastal surges of 25 feet or more. Such surges are only exacerbated by higher mean sea level. The impact on storm surge will be most apparent where land lies close to or even below sea level and where hurricane frequency is relatively high, such as the U.S. Gulf Coast and the Mid-Atlantic Coast.

This story was updated at 9:43 p.m. EDT with comments from AIR Worldwide